NEW YORK – Mike Napoli stung Masahiro Tanaka by hitting a solo home run with two outs in the ninth inning, lifting Jon Lester and the Boston Red Sox over the New York Yankees, 2-1, Saturday night.

Napoli had struck out in his previous two at-bats before lining an opposite-field drive into the first row of the seats in right. Napoli, who also homered off Tanaka at Fenway Park in late April, raised his right arm as he rounded first base.

The Red Sox won for just the third time in nine games. The victory made the defending World Series champions 37-44 at the midpoint of the season — it’s the first time since 1997 that Boston has been under .500 at the halfway mark.

Lester (9-7) held the Yankees hitless until the sixth. He gave up an unearned run and five hits in eight innings, striking out six and walking two.

Koji Uehara pitched a perfect ninth for his 17th save in 18 chances.

Tanaka (11-3) took the hard-luck loss. The top winner in the majors and AL ERA leader allowed seven hits in a complete game, striking out eight and walking one.

The matchup between Lester and Tanaka shaped up as a pitchers’ duel, and it certainly was. Lester improved to 13-6 lifetime against the Yankees, including a loss to Tanaka in Boston on April.

Lester and Uehara came through for a Red Sox team that has scored three runs or less in 12 of its last 14 games.

An odd sequence ended the Yankees eighth. Jacoby Ellsbury tried to steal second with two outs and the fans cheered when catcher David Ross’ throw skipped into center field. As Ellsbury headed toward third, however, the crowd began to realize strike three had already been called on Mark Teixeira.

Earlier in the inning, second baseman Dustin Pedroia made a nifty pickup and glove flip to start a double play on Derek Jeter.

Ross homered in the Boston third, launching a drive far over the left-field fence. Tanaka muttered to himself after the ball cleared the wall.

Tanaka has demonstrated a deft touch at escaping jams, and did it again the next inning after Pedroia led off with a single and David Ortiz doubled.

Tanaka struck out Napoli and Stephen Drew, then got Xander Bogaerts on a grounder to keep it at 1-all. Tanaka clapped his hand into his glove, jogged off the mound and fist-bumped with Jeter.

Lester, who threw a no-hitter against Kansas City in 2008, held the Yankees hitless until Brett Gardner bounced a leadoff single up the middle in the sixth. That preserved a very long streak — no one has pitched a complete-game no-hitter vs. the Yankees since Hoyt Wilhelm in 1958, although six Houston pitchers combined to do it in 2003.

Page 2 of 2 - Lester’s bid was extended with two outs in the fifth when Yangervis Solarte was called out on a video review, taking away an infield single.

Pedroia opened the next inning with a single, and tried to test the arm of Ellsbury, his former teammate. The Yankees center fielder made an accurate throw and Pedroia was called safe, but he was ruled out after New York challenged the umpire’s decision.

The Yankees scored in the third when Brian Roberts reached on Drew’s error at shortstop, Solarte was hit by a pitch, Gardner sacrificed and Jeter had an RBI grounder.

NOTEBOOK

The Red Sox promoted highly touted prospect Mookie Betts from the minors, hoping he might be able to boost a lineup that’s had trouble scoring runs all season. The sagging World Series champions selected the contract of the 21-year-old outfielder from Pawtucket and sent promising right-hander Rubby De La Rosa to their top farm club.